Mason 140 - SEATYLOCK


Mason 140

World's Lightest Sold Secure Diamond U-Lock!

Unique triangular crossbar profile for best strength/weight ratio. Double deadbolt locking mechanism for protection against twist attacks. *Mounting Bracket sold separately.

Hear what our customer has to say about his Mason 140



    Customer Reviews

    Based on 7 reviews
    Sturdy lithe lock

    We bought the smallest Mason for our 11-year-old son to lock his bike at school. It is compact enough to carry in his backpack and is easy to lock. Previous lock used had problems with the key breaking and wearing out. We are not afraid with the Mason for this to happen. The mechanism is foolproof and with 3 keys, you cannot get wrong.

    Rick Shaver
    Great D-lock

    The Mason is a high quality D-lock that protects my bikes and seems better made than my On Guard locks. I like the feature that it holds itself together after being unlocked until you gently pull it apart.

    Great all around lock for Segway E-Scooter E45 / E22 Models

    Purchased the U-lock for use on Segway Ninebot E45 scooter and it works great for locking around either the stem/folding mechanism.

    Tried out some of the local bike parking spots over the weekend without issue.

    Key highlights of the design are being lower weight compared to many competing locks and extra level of security from the dual shackle locking design.

    The automatic lock cover feature is pretty slick and I imagine will add to long term reliability of the U-lock.

    Lightweight & strong lock

    Fulfilled my expectations. Also, very helpful customer service.

    Greg Paul
    So far so good!

    Lightweight but Gold level strength. Winning combo!

    Solid lock

    I purposely wanted a lock with small inner dimensions to minimize air space inside the lock and deter against prying attacks. This lock is exactly what I was looking for and is big enough to fit around my bike frame and bike racks/parking meters/posts in San Francisco while leaving a minimal amount of air space inside the lock. Haven't had the lock tested yet luckily but it seems to be made of high quality materials with good craftmanship. Also extremely light for a gold-rated lock. I did a fair amount of research on bike locks after having my last bike stolen using a pry attack against my u-lock and settled on the seatylock plus hexlox for my wheels.

    Sharon Arbel
    Mason 85/140 Grey

    I have received the Lock very good packaged, and on time. this lock is very well made and super attractive! I found the lock was easy to use and I love that it comes with a bike mount and 3 keys.

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